There are two categories of fax message routing, commonly called primary and secondary routing. Primary routing is the process whereby fax messages are sent directly to their final fax telephone number. Since many users share a common fax telephone number, a second, or secondary, level of routing is required to send the message to its correct shared device user. Primary routing of fax messages today is generally performed by either manually dialing telephone numbers, sometimes abbreviated by "speed dialing". Secondary routing is most commonly done manually, wherein the incoming cover sheet containing the name and organization of the intended recipient of the fax message is read by a human and the message is hand delivered by a messenger.
It is customary to use a pre-printed cover sheet as the first page of a multi-page facsimile message so that the message is delivered to its intended addressee, since many people tend to share a facsimile unit. Cover sheets are filled in with information such as the name, organizational name, telephone number of the sender, and the name and address of the intended recipient. Also, the number of pages to be sent is included to enable the recipient to determine if any pages are missing from the transmitted document.
Primary cover sheets are prepared automatically today when the message to be transmitted is created using a computer. For a fax message transmitted by MCI or E-mail, the computer will transmit an automatically prepared cover sheet.
Facsimile messages may be routed to end recipients sharing a single telephone number by the combined use of computer-added digital information in the header of fax messages generated by the computer and the manual use of touch-tone signal generation and the OCR reading of a cover sheet.
While the optical character reading of the cover sheet is known art, there are a number of limitations. Typewriting is required in most cases, since the state of the art of the reading of hand printed characters is presently limited.